Automatic trailer brake control



Sept. 13, 1938. w. D. STRONG 2,129,715

AUTOMATIC TRAILER BRAKE CONTROL Filed Sept. 21-, 1937 2 Shets-Sheet livy.

Ill

L. i I n ventor WQZ terfi. Jozzg 1 1 iiorneus Sept. 13, 1938. w, D,STRON 2,129,715

AUTOMATIC TRAILER BRAKE CONTROL I Filed Sept. 21, 1937 2 Sheets-Sheet 2WaZzezj Sta 72y,

Patented Sept. 13, 1938 UNITED STATES PATENT OFFICE Claims.

This invention relates to means for controlling the brakes of a trailerwhen connected with a motor vehicle or other towing vehicle, the generalobject of the invention being to provide a 5 latch member for normallyholding the parts in a position with the brakes released, governor meansoperated by a rotating part of the trailer for releasing said member,means for applying the brakes of the trailer when the same moves towardthe motor vehicle and means for holding the brakes applied when theparts are in a certain position, such as when the vehicles are movingdown a grade and the trailer is crowding the motor vehicle.

This invention also consists in certain other features of constructionand in the combination and arrangement of several parts, to behereinafter fully described, illustrated in the accompanying drawingsand specifically pointed out in the appended claims.

In describing the invention in detail, reference will be had to theaccompanying drawings wherein like characters denote like orcorresponding parts throughout the several views, and in which:--

Figure 1 is a top plan view of the front portion of the chassis of atrailer, equipped with my invention.

Figure 2 is a longitudinal sectional view through Figure 1.

Figure 3 is a section on the line 3--3 of Figure 1.

Figure 4 is a section on the line i--t of Figure 1.

Figure 5 is a section on the line 5-5 of Figure 3.

Figure 6 is a, section on the line 6-45 oi Figure 2. 1

In these drawings, the letter A indicates the front portion of thechassis of a trailer, the front wheels being shown at a and the brakedrums of these wheels are shown at a.

In carrying out my invention I provide a tubular shaft l which isrotatably supported in 55 the vehicle is moving the governor'will movethe transverse position by one of the side bars of rod 6 longitudinallyso that the rod will cause movement of a bellcrank i pivoted to a partof the chassis and this movement of the bellcrank will be communicatedto a rod 8 which is connected to an arm 9 of an angle latch it which isnormally held by a spring H in engagement with a keeper recess i2 formedin the tongue it of the trailer and which is adapted to be connected tothe towing vehicle. This tongue is slidably supported in the front endof the trailer by the parts M and it has a socket in its rear end forslidingly receiving the reduced part l5 of the sliding member it whichis supported for sliding movement in the member ll attached to a part ofthe chassis. The member it is connected in any suitable manner with thebrakes of the trailer as shown generally at it and in such a manner thatas the member it is either moved rearwardly or is held against movementwhile the trailer moves forwardly the brakes will be applied. Thismember l6 has ratchet teeth l9 on its underside which are adapted to beengaged by a dog 20 pivotally supported on a part of the chassis andoperated by a spring 21! which tends to hold the dog in engagement withthe teeth. A link 22 is connected with the dog and has a slot 23 thereinfor receiving a pin 2% on a hanger 25 depending from the tongue is.

A small lever 28 is pivoted to the bracket 29 supported from the chassisand to which the rear end of the spring 2i is connected. The lower partof the lever has a hole therein through which the rod 8 passes and alink it connects the upper end of the lever with the latch 20. A collar3! is adjustably connected to the rod 8 in such a position that as therod is moved rearwardly by the operation of the governor said collarwill engage the lever so as to rock the same on its pivot which willcause the link 30 to move the latch 2t to releasing position from atooth 09 of the member it.

When the parts are so arranged that the latch it is engaging the keeperrecess l2 in the tongue ii the pin 2% will be in a position holding thelink 22 with the dog it out of engagement with the teeth of the member86 so that the springs of the brakes of the trailer will hold saidbrakes in. released position. Thus the motor vehicle can pull thetrailer and then when the speed of the trailer reaches a certain point,say two or three miles per hour, the governor will actuate the parts soas to release the latch in from the keeper recess l2 and then the partswill be ready for the application of the trailer brakes when neces-'sary.

If the trailer should move toward the motor that the advantages andnovel features of th vehicle, forany reason, such as sudden stoppageinvention will bereadily apparent.

of the motor vehicle or when the motor vehicle It is to be understoodthat changes may be and the trailer are traveling down a grade the madein the construction and in the combination,

5 shoulder l8 formed at the junction of the reduced and arrangement ofthe several parts, provided 5 part IS with the member I 6 will engagethe rear that such changes fall within the scope of the end of thetongue, which'is held against sliding appended claims. movement by beingconnected with the motor Having described the invention, what is'claimed vehicle, and thus further movement of the memas new is:--

10 her I6 will be stopped and as the-trailer continues 1. Automaticbrake control means for a trailer 10 toward the motor vehicle therelatively stationary comprising a tongue slidably supported in themember It will cause the brakes of the trailer to front part of thetrailer and adapted to be conbe applied. However, as soon as the vehiclemoves nected to a towing vehicle, means for applying the forwardly ofthe trailer a pull will be exerted upon brakes when the trailer movesforwardly relative 16 the tongue which will then make the member ii tothe tongue, latch means for latching the tongue free to move so that thesprings of the brakes will to the trailer, governor means actuated by amovrelease the same. able part of the trailer for releasing the latch Ingoing down a grade the trailer will crowd the means. motor vehicle andto prevent the continual appli- 2. Automatic brake control' means for atrailer 20 cation of the brakes and the release of the brakes comprisinga tongue slidably supported in the 80 on a down grade, I provide theratchet means front part of the trailer and adapted to be conincludingthe teeth IS, the lever 28, and the dog nected to a towing vehicle,means for applying the 28. Thus when the brakes are applied on goingbrakes when the trailer moves forwardly relative down a grade and thevehicles are traveling at to the tongue, latch means for latching thetongue 5 ,such a slow speed that the governor will not actuto thetrailer, governor means actuated by a mov- 26 ate the rod 8 and thetongue I! is in 'a position. able part of the trailer for releasing thelatch with the recess I! out of alignment with the latch means, meansfor holding the brakes in applied ill, the pin 24 will be in anintermediate part of the position and means for releasing such holdingslot 23 so that the spring 2| can engage the dog means when the tonguemoves forwardly relative 30 "with a tooth I8 and as long as the partsremain to the trailer. 80 in this position the brakes are held appliedand 3. Automatic means for controlling the brakes the brakes will not bereleased until the parts are of a trailer comprising a tongue slidablysupported moved to a posititon where the pin 24 will exert a in thefront part of the trailer and adapted to be I pull on the member 22 torelease the dog. Of connected to a towing vehicle, latch means forcourse, if the vehicles pick up suflicient speed to holding the tongueagainst movement in the 85 cause the governor to actuate the rod 8 thenthe trailer, governor means actuated from a movable collar 3i engagingthe lever 28 will move the latch part of the trailer for releasing thelatch means,

20 out Of engagement w a ooth o t e P a member slidably supported in thetrailer and which would permit the brakes to be released if connectedwith the brakes, a part on the member the trailer is not crowding thevehicle. 'I'heparts engaging the rear end of the tongue when the 40 areso constructed and a r n that th p n W111 trailer moves toward thetowing vehicle, ratchet age the front end of the slot 28 to exert a pullmeans for holding the member in position with p n t e l nk 22 to e s t edog 0 J 88 the the brakes applied, said ratchet means including a latchI0 is entering the recess l2and then the spring pressed dog, a linkconnected with the dog parts are held in position with the brakesreleased and having a-longitudinal slot therein, a member 45 and thisenables the motor vehicle to be backed depending from the tongue andhaving a pin which in turn, of course, backs the trailer. thereonpassing through the slot, the pin moving When the vehicles are goingdown grade and the dog to releasing posititon upon forward movethedriver of the pulling vehicle wishes to stop and ment of the tonguerelative to the trailer.

then back, the trailer would come to a stop in the 4. Automatic brakecontrol means for a trailer to forward position so that the latch l0could not comprising a tongue slidably supported in the engage therecess I 2. However, as the governor front part of the trailer andadaptedto b ce8ed to act on t e od 8 t p g 2| would nected toatowingvehicle, meansfor applying the place the latch iii in engagement withone of the brakes when the trailer moves forwardly relative teeth I! 0!t e member thus o d g the tothe tongue, latch means for latching thetongue 55 trailer brakes applied and preventing further to the trailer,means for holding the brakes in movement of the trailer. Then the drivercould applied position and governor means actuated by move forwardly thepulling vehicle a sufficient a movable part of the trailer for releasingthe amount to let the latch l8 engage the recess l2 and latch means andthe holding means w e the this would cause the parts 22, 2:, 24 and 25to trailer r a r n spee release the latch 20' thus fre ing the brakes so5. Automatic brake control means for a trailer that the driver can backboth vehicles. If latch comprising a tongue slidably supported in the 20was Omitted there would be no way of keeping front part of the trailerand adapted to be conthe brakes set when the pulling vehicle movesnected toa'towmg vemclemeans for applying the 65 ahead so that thetrailer would follow it and if an $152123; :535:23: gg ii z m im gg s xigz 522132 31 :22$: to the trailer, means for holding the brakes inbacked applied position and governor means actuated by a movable art ofthe trailer for releasin the Asit will beseen the governor acts tocontrol the latch mean: and the holding means the 70 latch and dogkeeping them from engaging trailer reaches a certain speed, and meansfor when the trailer is moving over two or three miles holding theholding means in inoperative position per hour which lets the tonguefree to apply he when the latch means is in operative position. brakeswhenever necessary.

It is thought from the foregoing description DAVID-STONG. 75

